Yeah, I second the paranoia recommendation. I don't enjoy weed, personally, so honestly I don't even know how big a lump a half pound really is... but I'd be really, REALLY careful about only ordering from a vendor who has really good reviews for large quantities. Remember, you're at more risk than the seller the way we do things here. Find somebody who either cares about their clients, or who understands that clients who get arrested do not come back to pay you more money (i.e. the most profits come from ensuring the safety of your buyers).